I have applied conditional formatting to a column of cells to highlight the cell red when the date contained in it is > 180 days. The formula applied to all of the cells is =TODAY()-180. Works perfect, however, there are cells with no values (dates) entered yet and they are also highlighted.

Ideally I'd like the cells with no date in them to remain white until a date is entered and then apply the conditions after a date is entered.

The cells I'm using are I46-I57. I46 is the only cell with a date now but eventually the rest will be populated and I'd like the formula to apply to them once the date is entered. So, can you provide and example of the formula?

I have several other columns that I'll be able to apply this to. Thank you!

The other columns will be totally separate. To be specific, I work in a hospital and each column represents a different lab which needs to be done every 6 months (Ex: "I" column is for liver function tests, "J" column will be for blood counts etc.). I'd like to enter the date the last lab was drawn and have it highlight when it becomes 180 days or longer since it was last done.

The blank cells represent a lab that wasn't drawn yet or just has not been filled in yet. I have to look them up indivudually and fill in as I go. I just don't want the blank cells to be highlighted. Thank you.

A new issue came up. For the lab values I need to highlight values when they are outside of a range (Ex: any value not between 30-80 need to be highlighted). I tried =ABS(C2)>D2 where C2=first value and D2=second value but that obviously incorrect.